Overload release drive clutch



4 Sheets-Sheet l Filed Oct. 28, 1946 w m m K J www W w a g. r. Q f f s m j S u if, i m @Q m. N N uw N A w i US KQ Q Q NN NN QN 1 R w N www Byg ,Q

` ATTORNEYS Jan. 3o, 1951 EHUNTAR 2,539,425

OVERLOAD RELEASE DRIVE CLUTCH Filed 001;. 28, 1946 4 Sheets-Sheet 2 INVENTOR JQ@ M BY@ ATTQRNEYS Jan. 30, 1951 F, HUNTAR 2,539,425

OVERLOAD RELEASE DRIVE CLUTCH Filed Oct. 28, 1946 4 Sheets-SheefI 5 INVENTOF;

` ATTORNEYS Jan. 30, 1951 F. HUNTAR 2,539,425

\ OVERLOAD RELEASE DRIVE CLUTCH Filed Oct. 28, 1946 4 Sheets-Sheet 4 f ATTORNEYS Patented Jan. 30, i951 Felix Hiintar; Livingston, N; J.; assigno'r totA11-reif-Y ican Gan Company,- New York, N." Y.; a corpo-J2 ration ot' NewV Jersey Application:ociosa-2s, 194e', sending. ioaifii 9 Glaii'ns.

This inventionrelates to af driving clutch mechj anisrnv and has particular reference to a s lip clutch which, is disposedjhetween two connected machines or different parts ofY al machine opere ating in synchronism. on diierent cycles, and whichY upon disengagefinentl may be' reset easily to" reestablish the' proper timed reiati'on between the machines or machine parts before againsetting them in operation;

In the operation or driving of machines or` different parts of' a single machine; slip'clutches usually: are employed for stopping the diierent machinesl or parts thereof during an abnormal condition arising in one machine orin' one sec'-4 tion of the machine. In machines operating on o single' cycle', tlieclutch parts may be'reengaged through a single revolution ,andA the parts re-v turnedv to their original timed relation. In connected machines which operate at different speeds orcyclesV ofoperatiom as for' ei;-` ample, ata ratio of lj to'l` or any ratio different than 1 tol, the reengagement or resetting of the clutch parts must correspond with theV proper timed relation of the machines, otherwise the clutch would reconnect the machines with' the machines outA of time; Hence serious damageto the machineswould result when they were set in operation.

fhel present invention contemplates a double slip cucchw'hicn is located between different machines, units or parts thereof which operate dtfdifferent speeds d1` cycles in tunedI relation and whichv is arrangeli` with Va driving" disk" and plurality ofcoopera'ting synchronizedl driven disks", the latter upon disengagem'ent'ofV theclutchf parts due to abnormal conditions, being rotatable relative to' each other through a; differential deivice for resetting the clutch and the portionsof the machines'-connected' therewith in a predeter-v mined timed relation.

n" object of the invention isthe" provision in connected machines, or parts thereoi of a, slip clutch mechanism wherein. the clutch mechanism is adapted to controll the' operation of them chinos; or parts thereof when they operate at different speeds or cycles, i. e., at ratios different than one to one.

f Another object is the provision of`such a Islip clutch mechanism'wherein theclutch mechanism, after disengagement due to an abnormal condition` in thernachine, can be reset for eiectivfe .operation only upon reestablishment of the prop; er' timed relation between the machines or/parts thereof.

Another object is the provision of such a rslipy stood frorfnjthje following description', which', taken in? Connection with th" @Gem-going, 'dra'wig'i discloses a preferred oeniimdirne:ntthereof. Referring@ the drawings: Figure risaiongitddinaisetionai view or d l driving clutchmedianism embndying'tnepreisnt invention vshowing `4the""partsr in operating posi?i tion;

Fig. 2; is" a' view similar tol showing the Clutch parte Separated With-f a'lckins key holding. me@ ill aufif.10lefitvel Ptmni Fig; 3-`is a; tran" erse' sectional 4View taken along che srolgenlines 3- 43 innig; A2, drawnto'a reduced scale, showing a gearidrive for resetting the clnt'ch parts;

Figi 4. .is a' tra'sisrsje'viw tialenlalgs the'liees in Fig.l l, drawn tofa rediicelscale, showing disk faces j and contersiink openings formed meren-.fdr receives th durch' has:

Fig. 51s an end view or tnemechanism shown in Fes, A1; and; 2., dawn i@ a iducisde la' viewed iflrll'the'rialfy with per@ bel'efi' We-rif parts inA section Vand' showing the relative position The drivgwhaft .l2 @iel2@ Whish meshes with' pifniriv4 .1.2121 ratio of four to one .is s relectedffor piirpos 'fof inusual-ion, pinion lzb win te one fourtthe diameter of the gear I2a. Pinion I2b is mounted on a shaft I2C which thus will be considered the key shaft on which a given set of operations depends.

In other Words, four revolutions of shaft I2c completes the desired cycle of operations. Therefore, drive shaft II and driven shaft I2, when operating together under normal driving conditions, will make one revolution for the desired cycle of four revolutions of the key shaft I2C.

An abnormal condition which blocks either shaft will disrupt the normal connection between shafts II and I2. The interposed clutch mechanism of the present invention will allow a change of relative shaft positions without damage. This relative change creates an abnormal relation between shafts. Resetting is done through shaft I2, which may have to be rotated a maximum of nearly four revolutions with drive shaft II stationary, before it is again properly related to the drive shaft.

The present clutch mechanism insures proper setting and prevents establishment of any shaft relations, except that relation which will give the desired cycle of operation as to the key shaft I2c.

In the event that the driven shaft I2 is forced out of its predetermined position with respect to the drive shaft II due to an abnormal condition arising in one of the machines or part thereof, provision is made for restoring the proper timed relation by turning certain of the clutch parts, while other parts are held stationary, thereby reestablishing the proper cycle of operations in the respective machines or parts thereof.

The shaft II has a shaft extension I3 which may be formed as an integral part or may be secured as a separate part on the inner end of the shaft (Figs. 1 and 2). Shaft extension I3 carries the driving parts of the clutch mechanism and these are referred to as a driving member A. Driving member A is connected through clutch driving instrumentalities B to a driven member C which is mounted to operate with the driven shaft I2.

Drive member A comprises a driving body I4,

formed with a bearing I5 which is keyed onto the shaft extension I3. Driving body I4 is provided with a plurality of outer holes I6, and a plurality of inner holes I'I. There are three of each of the holes I6, I'I. Outer holes I6 are preferably equally spaced one from another at an angular distance of 120 degrees, their radial lines passing through the center of the body I4 and through the center of the shaft extension I3. These outer holes I6, each of which is disposed at a different distance or radius from the center, will be referred to as inside, intermediate and outside, outer holes in accordance with each distance from the center.

The inner holes I'I are also equally spaced around the shaft center and are located at different distances or radii from the center. These three inner holes I'I may be logically referred to as inside, intermediate and outside, inner holes, in accordance with each distance from the center. The outside outer hole I6 is on the same radial line as the outside inner hole I'I. The intermediate outer and inner holes are likewise radially aligned, as are also the inside outer and inner holes. a selective registration of the clutch parts, as will be further explained.

The clutch instrumentalities B comprise clutch elements or balls I8 which engage with disk elements I9, 2D (Figs. 1, 2, 3 and 4). The clutch This permits what may be termed f balls I8 are carried in the holes IB, I 'I and engage in countersunk recesses or sockets 22, formed in alignment therewith, in the faces of the disk elements I9, 20.

The balls I8 in the inner holes Il which seat in sockets formed in the face of the disk element I9, may be considered primary clutch parts. The balls in the outer holes I5 which seat in sockets formed in the face of the disk element 20 logically constitute secondary clutch parts.

Fig. 4 shows these recesses or sockets 22 in their normal relations, that is, when the disk elements I9 and 20 are in their normal clutch driving positions. These recesses may be designated in the same terminology as used for the holes I6 and Il. When so expressed, Fig. 4 shows outside, outer and inner recesses 22a and 22h of the respective disks 2U and I9 as being on the same radial line passing through the center of the shaft extension I3.

In like manner the intermediate, outer and inner recesses, of disks 20 and I9, marked 22e and 22d, are aligned. The same also holds for the inside, outer and inner recesses, marked 22e and 221. It is this radial alignment of outer and inner recesses of the elements 29 and I9 that constitute the selective clutch positioning mentioned above. This is the proper angular setting between the shafts II and I2 for rotation together in normal operation.

The disk element I9 is located in a counterbore 23 of the driving body I4 and is rotatably carried on the shaft extension I3. Disk element I9 frictionally bears under the driving load of the clutch against a flange 24 formed on the inner end of the shaft extension I3. The disk element is secured to the inner end of a hub 25 which surrounds the flange 24. The hub 25 is secured at its outer end to a bevel gear 26 mounted on the driven shaft i2.

The disk element 20 is freely carried on the hub 25 and preferably is spaced from the disk element I9. Spacer pins 21 are slidably carried in the holes I5 and engage against the outer row of balls I8 and thus are included as part of the clutch instrumentalities B.

Driving member A includes a pressure plate 28 Which is carried on the bearing I5. The pressure plate 28 has an inner face 29 which frictionally engages the inner balls I8 and the pins 21 which in turn frictionally engage the outer balls I8 for keeping the two sets of instrumentalities B in driving engagement (Fig 1). In order to maintain the pressure plate 28 in driving position, a spring 32 is provided which surrounds the bearing I5 and which is interposed between the pressure plate and a locking nut 33. The locking nut 33 is adjustably mounted on the shaft II by means of which a predetermined yielding pressure may be set up against the plate 28 through the spring 32 and effective for different clutch driving conditions (see also Fig. 2)

During normal driving operations the clutch parts are in the position illustrated in Fig. l. Should an abnormal condition arise such as a jam in the machine that is being driven, the shaft I2 stops rotating while the driving shaft II continues to rotate temporarily. This stoppage of driven shaft I2 and the gear 26, hub 25,y

and disk element I9 connected therewith, forces both inner and outer balls I8 out of their sockets 22. The displaced balls push the pressure plateE 28 outwardly against the resistance of the spring 32.` Thus the clutch instrumentalities B becomel mate.. is. utilized;I forr actuating.: an. electric switch or;` cytl'ier.VV tripf. device, not. shown', which` is ausual componenti. partof slip. clutches and: this switch or; device acting upon theisourceiof'power of the machine stops; theA rotationk of the drive shaft; II tQrrender-the entire machine inoperative so.: that they: abnormal' condition. may be remedied.

Since it is almost. impossible to stop;.the; ro.- tation off' the drive shaft. III;A simultaneously with the stoppage of the driven shaft I2, ani. unpredictabley amount of overthrow. of the drive shaft takes place and. this; throwsV the driving member andl therdriven member. C out oftheir' proper timedi relation; During. this: overthrow movement ofi the shaft II, theouter balls I8 are rotating alongtheadjacentface of the disk elementtZ and the-inner ballsalong the adjacent face or the disk elementy I9. Since allpf the balls: wereforced. outzof their sockets-at thetime thev shaftN If-2 stopped; all of' the. ballsv at'that, time combine-Ix) hol'dthepressure plate so that: the spring32 is compressedV momentarily, as.- Will'` be further described.

A- complete overthrow revolution off. the driving body |42 alongside of` the now. stationary disk element I9, carrieslthe inner balls Iintoalignment'V withL their sockets; 22h; 22d; and. 227, see Fig. 4,' but'the disk' element.: 28.. is turning; at a diierent rateot` rotation ofitheldriving body. I4 sol-that. the=sockets.2`2a, 22e and.2.2eof; the. disk 20l are' not-` aligned with.- the outer balls I8. Under these conditions-.the cuter.v balls.: will pre,- ventl seating. off the clutch parts. Iny like man:- ner; aI complete overthrow revolutionas tothe disk element 2.0f1wouldf. carry. theouter balls I8 intoalignmentzwith theirsockets,v but theinner ballswill2prevent1seating; of` the clutch. parts. One setz of? aligned'. balls, even. though. thekr balls might' drop intoI their: sockets; there being no spring pressure tohold-J them in their. seats;v is znot l suiilcient` to .operate the engaged parts.

Tofrelieventhepressure of the ballsagainst; the engaged faces of the disky elQmentsZBZand-i I9; provision` is made to .hold"the..displaced pressure pla-ten28 inl-its forcedoutposition against the-resistance off the spring*v 32, so=that the: pressure will beetake-nfoff the balls-I 8 whilethe driveshaft isi-brought, toa fullistop;V This l.holding of the pressure platel in'l anv inoperative position: is brought about through the action of. a plurality of flat locking 1 keys 34,; whichV are rectangular :in cross-section (Fig. 8). A'

There-are threeI keys 341 andthey-arefcarried in key4 slots 352 formedin the pressureV plate .285..

They-inner endsctthe keys 34l engage in anannulargroove. 361'formed linthe-*bearing I5; The keys: 34*` are moved radially inward bypressure devicesior.V spring actuated plungers 3l fvvhich-are carried'in bor-esl 38am-the pressure platev28l rThe sionI springs: 4-1I which areretained in place-f by hollowed screws 42 threadedly. secured in the pressure.- plate- 28'; Plungers 31 r like 'the hollow screws 42-7 are. formedfzwith .recesses within which theaends .of-;the.springs=.4-I are locateds In order to restore'` the clutch parts'to'-y their proper timed relation, the locking keys 345 must bewithdrawn from .the -annular groove 36.-

ThisA is;.done while the driving/parts are held station-Y- The .l key4 releasel ring; normally:isgzrotatablef. with the;` pressureV 6i platee 218.; but. isi movabIe relative thereto. while resettingfthe clutchaparts. The ringV 44 is; carried ini annular; grooves 45, 4E. in. the pressure plate 28 andy is held therein by aretaining ring. 41 locatedi and'securediina face groove. 48 (seel also Figs. 2, 5, 6 andv'l).

The. key release ringI 44 isy provided.r with'. three pockets 5I, one for` each. of` the locking keys (Fig. 5); Thev pocketsl are each formed; with a cam wall. 52 which: is engageable by a` semis circular extension 53. formed onA one. face off each ofthe keys- 34 (see also Eig. 8) for withdrawing the'l keys outv` of the annular slot 3.61 to. release themr from.A their locked positionY upon. rotation of` therelease ring 44. This action allows: the spring 32 toare-exert or restore itseffective pressure against the pressure plate 28 andthe clutch instrumentalities B' preparatory toresetting: the clutchparts in proper timed relation.

Rotation of thel keyreleasering 44 relative to the: pressure plate. 28 is: effected: manually: by a bar or other suitableY tool 54: which is inserted intoany one: of a seriesof holes55 formed in the-key release ring 44. Following the-insertion of the bar 54 andthe movement off the ring: 4.4 toreleasethe locking keys; the bar may be held to keep the driving members from turning While the driven member C' is rotatedY relative thereto.

Turning of the driven member C is effected manually by a bevel gear-518 Whichmesheslwith and rota-tes the bevel gear 2 6. Bevel gear 58`fmay be rotated in: any. suitable manner, as for exL ample, by. a'hand wheel 59. connected'to the bevel gear 58'Lthrougha shaft 68. The-rotating-'action elects the turning ofi the hub 25' and the disk element I9?y relative tothe driving body I 4J and the balls I8 in theV openings I1.

Thehub 25,(l5li'gs.y 1; 2 and 3) carries a plurality of spaced'apart intermediate gears 62S, arranged in a circle concentric with the. drivenshaft- I2' and located in clearance openings formed in the hub. There are three of these gears and they form part of 'a differential gear. drive unit which effects the relative movement' of' the disk elements I9, 28 forreestablishing a proper timed* relation of the respective sockets 22 withthe clutch balls I8. Thev gears 62 are--carriedonA pins- 64 which are secured-in the hub 25 inany suitable manner.`

Thefintermediate gears 62" surround?` and meshwithA ay geary E55Y secured totheinner end ofthe driving shaft' I I mesh with internal gearV teeth66 formed in theY disk element 28. Thus, as thehub 25`- is turned to rotatek the disk element I8, the disk element 291 also is rotated relative thereto but at a different speed ofA travel. If the ratio of the driven machine to that of the driving machine is iouri to one, which is the arbitrary ratio selected to illustrate the present invention, the gearing re quired betweenl the disk. elements' is such that" forevery furrevolutionsofthe disk element I9; the diskelement 253 will make ve turns. Whatever this ratio may be, the two disk elements I9, 2U `will be brought into proper timedrelation only when1 their ball sockets 22 are brought intoY such relative positions as-to permit the balls I8 to snap backv into the-sockets of both disk elements When this takes place, the

at the same time timed relation of the disks has been reestablished and? the clutchv mechanism is` thusreset andiis Before again -ready forstarting of the-machine. starting the-machineytheV holding bar 54 is'reif movedfrom thekey'release ring 44;

During normal operations of` the engagedYV The intermediate gears 62 also clutch, the driving and driven parts operate at the same speed, thus the meshing gears 62, B and 66 remain stationary relative to each other.

A step by step description of the resetting of the clutch mechanism under a particular set of circumstances will now be given by way of further example. It will be assumed that the overthrow of the drive shafll II, after stoppage of the driven shaft, has carried the driving body I4 .with its outer and inner balls I8 one and a half turns relative to the disk element I9. The disk element 20, during this overthrow, has rotated in the opposite direction V8 revolution. This is by reason of the one to four ratio between gear 65 and gear teeth 66. None of the balls I8, therefore, are on the same radial lines of their several sockets.

To restore a proper setting to the clutch mechanism, the locking keys 34% rst are released as previously stated, and pressure of the spring 32 is made effective through the pressure plate 28 on the balls I8. Then the handwheel 59 is rotated and through the gear 50, this turns the driven parts which are the gear 2B, hub 25 and disk I9. The shaft i I, the gear 65 and the dr'iving body Id, including the balls I3, are now stationary.

Since the set of operations dependent on the key shaft I2c in most cases will follow in a given sequence, the parts will not be turned back in setting but will be turned forward asto the overthrow relation. The disk element I9 and hub carry the shafts 64 in a circle and the intermediate gears F52, therefore, move over the stationary gear 65. element I9 will be turned 21/2 revolutions which is the difference between 4 turns and the 11/2 of the overthrow. By this action, the sockets 2212, 22d and 22 f of the disk element i9 are aligned with the inner balls I8.

For this resetting movement of 21/2 revolutions of the disk element I9, the described gear connections with the disk element 23, i. e., the gears 62 and teeth E6, will rotate the element 2i) one fourth of a revolution more than 2% turns or a total of 31/8 revolutions. This aligns the outer sockets 22a, 22C and 22e with the outer balls I8. Since all of the balls at this time are. positioned correctly for engagement with their respective sockets, all will simultaneously enter under the action of the spring pressed pressure plate 28. The clutch therefore has placed the drive shaft II and the driven shaft I2 into correct driving position.

It should be understood that there is no intermediate position where this setting of the clutch can take place. The sockets 22 of both outer and inner disk elements 2D and I9, being at different distances from the center of the shaft extension I3, require a complete rotation of each element to align their outer and inner sockets with the outer and inner balls. By reason of the gear connections S6, 62 and 65, a simultaneous alignment of both disk sockets and balls can only take place at multiples of five turns for the disk element 2t and four turns for the disk element I9 while the gear 65 is stationary. Such multiple clutch settings will always properly `relate the two shafts II and I2.

It should be evident upon perusal of the drawings (Figs. l, 2 and 3) that to provide for other combinations or cycles of operation it is merely necessary to change the ratio of gear drive for the gears 62, 65, E6 through which the machineso r parts thereof may operate.

For this resetting the disk It is thought that the invention and' many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacricing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

l. A driving clutch mechanism for machines operating at different cycles in timed relation, comprising a driving member, a driven member, two disk elements carried on one of said members and rotatable together and also relative to each other, clutch elements located adjacent and coactive with each of said disk elements for connecting said driving and said driven members together in normal driving relation, means for exerting pressure on a said element to hold the elements in driving engagement said means yielding under abnormal conditions for disengaging said elements, and means for turning one of said disk elements relative to the other for establishing a proper timed relation between said driving and said driven members.

2. A driving clutch mechanism for machines operating at different cycles in timed relation, comprising a driving member, a driven member, two disk elements carried on one of said members and rotatable together and also relative to each other, clutch elements located adjacent and coactive with each of said disk elements for connecting said driving and said driven members together in normal driving relation, means` for exerting pressure on a said element to hold the elements in driving engagement said means yielding under abnormal conditions for disengaging said elements, means for turning one of said disk elements, and a differential unit located between one of said members and said disk elements and operable for turning the other of said disk elements for establishing a proper timed relation between said driving and said driven members.

3. A driving clutch mechanism for machines operating at different cycles in timed relation, comprising a driving member, a driven member. two disk elements carried on one of said members and having slip faces formed with a plurality of spaced countersunk openings, said disk elements being rotatable together and relative to each other, a set of clutch balls located adjacent and coactive with each of said disk faces to engage within said countersunk openings for con-` necting said driving and said driven members together in normal driving relation, spring means for exerting pressure on said sets of clutch balls to hold the latter in driving engagement with said disk faces said spring means yielding under abnormal conditions for disengaging said sets of clutch balls, and means for turning the said member carrying said disk elements to rotate the same for reengaging said countersunk openings with their respective sets of clutch balls to establish a proper timed relation between said driving and said driven members.

4. A driving clutch mechanism for machines operating at different cycles in timed relation, comprising a driving member, a driven member, clutch instrumentalities located between said driving and said driven members said instrumentalities comprising primary and secondary clutch parts movable in unison for connecting the said members together in normal driving relation, spring means for exerting pressure on said` clutch instrumentalities to heid the latter in driving engagement, said spring means yielding under abnormal conditions for disengaging said clutch instrumentalities by movement between said primary clutch parts and said secondary clutch parts, a locking key carried in said driving member for keeping said clutch instrumentalities disengaged following the yielding of said spring means, and means for moving one of said clutch instrumentalities relative to the other for establishing proper timed relation between said driving and said driven members.

5. A driving clutch mechanism for machines operating at different cycles in timed relation, comprising a driving member, a driven member, clutch instrumentalities located between said driving and said driven members said instrumentalities comprising primary and secondary clutch parts movable in unison for connecting the said members together in normal driving relation, a yieldable spring for exerting pressure on said clutch instrumentalities to hold the latter in driving engagement said spring yielding under abnormal conditions for disengaging said clutch instrumentalities by relative movement between said primary and said secondary clutch parts, a plurality of locking keys carried in said driving member for holding said clutch instrumentalities disengaged following the yielding of said spring, and means for moving one of said clutch instrumentalities relative to the other for establishing proper timed relation between said driving and said driven members.

6. A driving clutch mechanism for machines operating at different cycles in timed relation, comprising a driving member, a driven member, clutch instrumentalities comprising primary clutch parts and secondary clutch parts located between said driving and said driven members for connecting the said members together with said primary and secondary clutch parts in normal driving relation, spring means for exerting pressure on said clutch instrumentalities to hold the latter in driving engagement said spring means yielding under abnormal conditions for disengaging said clutch instrumentalities, a plurality of locking keys carried in said driving member for holding said clutch instrumentalities in an inoperative position following the yielding of said spring means, a pressure device also carried in said driving member for engaging each of said locking keys for holding said locking keys in locking position, and means for turning said driven member relative to said driving member for reengaging said clutch instrumentalities with said primary and secondary clutch parts in a definite relation for establishing proper timed relation between said driving and said driven members.

7. A driving clutch mechanism for machines operating at different cycles in timed relation,

, comprising a driving member, a driven member,

clutch instrumentalities, comprising primary clutch parts and secondary clutch parts located between said driving and said driven members for connecting the said members together with said primary and secondary clutch parts in normal 'driving relation, a yieldable spring for exerting an inoperative position following the yielding of said spring, means carried in said driving member for releasing said locking keys and for holding them in released position for restoring the effectiveness of said yielding spring, and means for turning said driven member relative to said driving member for reengaging said clutch instrumentalities with said primary and secondary clutch parts in a dente relation for establishing proper timed relation between said driving and said driven members.

8. A driving clutch mechanism for machines operating at different cycles in timed relation, comprising a drive shaft and a driven shaft interconnected through the clutch mechanism, a gear carried on the inner end of said drive shaft, a driving member mounted on said shaft, a driven member mounted on said driven shaft, said driven member including a hub having disk elements carried thereon, clutch elements located adjacent and coactive with each of said disk elements for connecting said driving and said driven members together in normal driving relation, a yieldable spring for exerting pressure on said clutch elements to hold the latter in driving engagement with said disk elements said spring yielding under abnormal conditions for disengaging said clutch elements, a plurality of locking keys carried in said driving member for holding said clutch elements in an inoperative position following the yielding of said spring, a key release ring movably carried in said driving member and having a plurality of cam walls for engagement with said locking keys for withdrawing said keys from locked position, intermediate gears carried in said hub and meshing with said drive shaft gear and with teeth formed in a said disk element for rotating said disk elements relative to each other for reengaging the latter with their respective clutch elements, and means for turning said driven member and reengaging said clutch elements to establish proper timed relation between said drive and said driven shafts.

9. A driving clutch mechanism for machines operating at different cycles in timed relation, comprising a driving member, a driven member, clutch instrumentalities located between said driving and said driven members for connecting the said members together in normal driving relation said clutch instrumentalities comprising primary and secondary clutch parts, means for exerting pressure on said clutch instrumentalities to hold the latter in driving engagement said means yielding under abnormal conditions for disengaging said clutch instrumentalities, means for turning said driven member relative to the driving member for establishing proper timed relation between said driving and said driven members when said normal driving relation is disrupted,land a differential unit interposed between said driving and driven members for rotating one clutch instrumentality at a different rate from the other when engaging said primary and said secondary clutch parts.

FELIX HUNTAR.

REFERENCES CITED UNITED STATES PATENTS Name Date Rancke Sept. 2'7, 1932 Number 

